Which excerpt from "Going Back to School" adds to the theme that being unhappy in a particular situation can make one feel imprisoned?

One splendid instant – back in the great room,
Curled in a chair with all of them beside
And the whole world a rush of happy voices,
The boat ploughed on. Now Alcatraz was past
And all the grey waves flamed to red again
At the dead sun's last glimmer. Far and vast
With laughter beating in a clamorous tide. . . .
Saw once again the heat of harvest fume
Up to the empty sky in threads like glass,
The ship slowed, jarred and stopped. There, straight ahead,
Were dock and fellows. Stumbling, he was whirled
Out and away to meet them – and his back

Question

Which excerpt from "Going Back to School" adds to the theme that being unhappy in a particular situation can make one feel imprisoned?

One splendid instant – back in the great room,
Curled in a chair with all of them beside
And the whole world a rush of happy voices,
The boat ploughed on. Now Alcatraz was past 
And all the grey waves flamed to red again 
At the dead sun's last glimmer. Far and vast
With laughter beating in a clamorous tide. . . .
Saw once again the heat of harvest fume
Up to the empty sky in threads like glass,
The ship slowed, jarred and stopped. There, straight ahead,
Were dock and fellows. Stumbling, he was whirled
Out and away to meet them – and his back

Renne · Answer

"Every day felt like a struggle, and I couldn't wait for the final bell to ring so I could escape the prison of school."